A dog may never achieve perfectly fresh breath, but if his mouth odor is bad enough to make you gag, he may have a more serious problem going on in there! Terrible dog breath is the main sign of early dental disease, which can lead to myriad health issues if left untreated. Adding dental washes to your dog’s water bowl can help remedy bad breath and its causes. Similar to human mouthwash, dog dental washes kill bacteria and fungus, and reduce plaque. They are more effective than brushing at getting to hard-to-reach parts of a dog’s mouth, and since most pups start to show signs of periodontal disease around age three, the time to start washing is now.